Hydrocarbon conversion system, and a process and catalyst composition relating thereto

ABSTRACT

One exemplary embodiment can be a process for making a catalyst including an effective amount of iron for catalyzing one or more reactions in a hydrocarbon conversion system. The process can include grinding and coating the particles. The ground particles can have an effective amount of iron, and substantially all the particles may have a maximum dimension no larger than about 130 microns. The coating can have an effective amount of one or more hydrocarbons to provide the catalyst with improved flowability.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Division of copending application Ser. No.12/412,738 filed Mar. 27, 2009, the contents of which are herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention generally relates to a hydrocarbon conversion system, andmore particularly to at least one of a process, a catalyst composition,and/or a slurry catalyst system relating thereto.

DESCRIPTION OF THE RELATED ART

Catalysts are often used in hydroconversion processes. In thehydroconversion of heavy oils, biofuels, and coal liquids, typically acatalytic slurry system is utilized. In such systems, often largeamounts of catalyst are utilized.

Typically, these catalysts are relatively inexpensive and do not containvaluable metals, such as noble group VIII metals. Often, such catalystshave a uniform, small particle size. Unfortunately, catalyst, such asiron sulfate, can meet the desired economic costs, but may also behydrophilic. As such, the catalytic material may absorb moisture andclump. Generally, the clumping of the catalyst creates problems whenattempting to disperse the catalyst into the hydrocarbon feed. Usually,the catalyst is dispersed into a hydrocarbon feed to form a slurrybefore the combined material enters a reactor. Thus, a catalyst materialwith a high degree of flowability is desirable. Typically, a catalystthat can be relatively hydrophobic and clumping resistant would have therequisite flowability.

SUMMARY OF THE INVENTION

One exemplary embodiment can be a process for making a catalystincluding an effective amount of iron for catalyzing one or morereactions in a hydrocarbon conversion system. The process can includegrinding and coating the particles. The ground particles can have aneffective amount of iron, and substantially all the particles may have amaximum dimension no larger than about 130 microns. The coating can havean effective amount of one or more hydrocarbons to provide the catalystwith improved flowability.

Another exemplary embodiment may be a slurry catalyst composition. Theslurry catalyst composition can have a catalytically effective amount ofone or more compounds including iron, and a coating including one ormore hydrocarbons having a melting point temperature of no more thanabout 250° C.

Yet a further exemplary embodiment can be a slurry catalyst system. Theslurry catalyst system may include an upflow tubular reactor. Generally,the upflow tubular reactor can receive a hydrocarbon feed and a slurrycatalyst composition. The hydrocarbon feed can include one or morecompounds having an initial boiling point temperature of at least about340° C. The slurry catalyst composition may include a catalyticallyeffective amount of one or more compounds, and a coating having ahydrocarbon with a melting point temperature of no more than about 250°C. for improving flowability of the slurry catalyst composition.

The embodiments disclosed herein can provide a slurry catalyst materialthat can be hydrophobic and resist clumping. As a result, the materialcan be easily handled and combined with a hydrocarbon feed to form aslurry before entering a hydroconversion reactor. The advantageousproperties allow the use of a relatively inexpensive material that canbe easily handled to facilitate forming a slurry for conductinghydroprocessing reactions.

DEFINITIONS

As used herein, the term “stream” can be a stream including varioushydrocarbon molecules, such as straight-chain, branched, or cyclicalkanes, alkenes, alkadienes, and alkynes, and optionally othersubstances, such as gases, e.g., hydrogen, or impurities, such as heavymetals, and sulfur and nitrogen compounds. The stream can also includearomatic and non-aromatic hydrocarbons. Moreover, the hydrocarbonmolecules may be abbreviated C₁, C₂, C₃ . . . C_(n) where “n” representsthe number of carbon atoms in the one or more hydrocarbon molecules.

As used herein, the term “zone” can refer to an area including one ormore equipment items and/or one or more sub-zones. Equipment items caninclude one or more reactors or reactor vessels, heaters, exchangers,pipes, pumps, compressors, and controllers. Additionally, an equipmentitem, such as a reactor, dryer, or vessel, can further include one ormore zones or sub-zones.

As used herein, the term “substantially” can mean an amount of generallyat least about 80%, preferably about 90%, and optimally about 99%, byweight, of a compound, class of compounds, or catalyst.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE is a schematic depiction of an exemplary hydrocarbonconversion system.

DETAILED DESCRIPTION

Referring to the FIGURE, one exemplary hydrocarbon conversion system 100can be a slurry reaction or bubble column system including a reservoir120, a holding tank 130, a heater 140, and a hydroprocessing reactionzone 150. Exemplary systems are disclosed in, e.g., U.S. Pat. No.5,755,955 and U.S. Pat. No. 5,474,977.

Typically, a hydrocarbon feed 104 can be provided, which may be a heavyoil vacuum bottom, a vacuum residue, a fluid catalytic cracking slurryoil or other heavy hydrocarbon-derived oils. Alternatively, thehydrocarbon feed 104 can be at least one of coal liquid or a biofuelfeedstock such as lignin, one or more plant parts, one or more fruits,one or more vegetables, a plant processing waste, one or more woodchips,chaff, one or more grains, one or more grasses, a corn, one or more cornhusks, one or more weeds, one or more aquatic plants, hay, paper, andany cellulose-containing biological material.

A reservoir 120 can provide a catalyst to be combined with thehydrocarbon feed 104. A resultant slurry 108, i.e., a combination of thecatalyst and the hydrocarbon feed 104 having a solids content of about0.01 to about 10%, by weight, can pass to a holding tank 130 beforebeing combined with a gas 112.

The gas 112 typically contains hydrogen, which can be once-throughhydrogen optionally with no significant amount of recycled gases.Alternatively, the gas 112 can contain recycled hydrogen gas optionallywith added hydrogen as the hydrogen is consumed during the one or morehydroprocessing reactions. The gas 112 may be essentially pure hydrogenor may include additives such as hydrogen sulfide or light hydrocarbons,e.g., methane and ethane. Reactive or non-reactive gases may be combinedwith the hydrogen introduced into the hydroprocessing reaction zone 150at the desired pressure to achieve the desired product yields.

A combined feed 116 including the slurry 108 and the gas 112 can enterthe heater 140. Typically, the heater 140 is a heat exchanger using anysuitable fluid such as the hydroprocessing reaction zone 150 effluent orhigh pressure steam to provide the requisite heating requirement.Afterwards, the heated combined feed 116 can enter the hydroprocessingreaction zone 150 including an upload tubular reactor 160. Often, slurryhydroprocessing is carried out using reactor conditions sufficient tocrack at least a portion of the hydrocarbon feed 104 to lower boilingproducts, such as one or more distillate hydrocarbons, naphtha, and/orC1 to C4 products. Conditions in the hydroprocessing reaction zone 150can include a temperature of about 340° to about 600° C., a hydrogenpartial pressure of about 3.5 to about 10.5 MPa and a space velocity ofabout 0.1 to about 30 volumes of hydrocarbon feed 104 per hour perreactor or reaction zone volume. A reaction product 170 can exit thehydroprocessing reaction zone 150.

Generally, the catalyst for the hydrocarbon conversion system 100provides a composition that is hydrophobic and resists clumping.Consequently, it may be suitable and easily combined with thehydrocarbon feed 104. Typically, the slurry catalyst composition caninclude a catalytically effective amount of one or more compounds havingiron. Particularly, the one or more compounds can include at least oneof an iron oxide, an iron sulfate, and an iron carbonate. Other forms ofiron can include at least one of an iron sulfide, a pyrrhotite, and apyrite. What is more, the catalyst can contain materials other than aniron, such as at least one of molybdenum, nickel, and manganese, and/ora salt, an oxide, and/or a mineral thereof.

Preferably, the one or more compounds includes an iron sulfate, and morepreferably at least one of an iron sulfate monohydrate and an ironsulfate heptahydrate. Oxidic iron-containing compounds obtained fromsources such as a limonite, a laterite, a wrought iron, a clay, amagnetite, a hematite, a gibbsite, or a Kisch iron can also be used. Oneparticularly desired material is ferrous sulfate. The ferrous sulfatecan either be a monohydrate or a heptahydrate. The monohydrate cancontain up to about 15%, by weight, water while the heptahydrate cancontain up to about 51%, by weight, water. The grain size of theparticles can have a largest dimension greater than about 0.2 millimeter(hereinafter may be abbreviated “mm”) but smaller than about 4.3 mm asdetermined by about 95% of the particles. In addition, the bulk densitycan range from about 880 to about 1,200 kg per meter-cubed.

The ferrous sulfate can contain less than 1%, by weight, of one or moreof the following, namely arsenic, cadmium, chromium, copper, lead,magnesium, manganese, nickel, and/or zinc. The ferrous sulfate can beobtained from any suitable source, such as QC Corporation of Baltimore,Md.

Typically, the catalyst particle coating can reduce the hydrophilicproperties of the particles. The catalyst can include a coating of ahydrocarbon having an initial boiling point temperature of at leastabout 250° C., or about 340° C., and/or a melting point temperature ofno more than about 250° C., or no more than about 80° C. In addition,the coating can include one or more hydrocarbons compatible with thefeed for processing in a hydrocarbon conversion system, such as a fluidcatalytic cracking slurry system. In addition, the coating can havesufficient moisture resistance to prevent agglomeration of thepelletized catalyst particles. Typically, the coating can include atleast one of a wax, a pitch, a deasphalted oil, a petroleum resin, and alow molecular weight polymer.

Preferably, the coating can include a pitch having a melting point nomore than about 250° C., preferably no more than about 225° C., or aparaffin wax having a melting point of no more than about 80° C.,preferably no more than about 60° C.

Preparing an exemplary catalyst can include providing a weight ratio ofcatalyst to hydrocarbon coating of about 200:1 to about 1:1, optimallyabout 2:1. As an example, the catalyst coating can be about 0.5 to about50%, by weight, of the total catalyst composition. A catalyst such asferrous sulfate may contain water, which can include lattice bond waterof hydration and/or physically absorbed water. A loss on ignitionadjustment can be used to calculate the amount of catalyst to becombined with the hydrocarbon coating. The loss on adjustment may bemade by measuring a weight loss on heating to about 600° C., andcomparing the results with the theoretical value calculated based on themolecular formula to obtain an adjusted molecular weight for use incalculating the amounts to blend in the formulations.

The hydrocarbon coating, such as a pitch or a paraffin wax, can becombined with the catalyst, such as iron sulfate, e.g., iron sulfatemonohydrate, in a continuous high speed mixer/heat exchanger.Optionally, a small amount of water, such as less than about 1%, byweight, based on the weight of the catalyst particles, can be added toaid in agglomerating the particles. The rotary shaft of the mixer can beequipped with paddles, which may atomize the mixture and convey itthrough the reaction chamber of the machine. The jacketed barrel and therotary shaft may be heated by steam or an oil-based heating medium abovethe melting temperature of the hydrocarbon coating, such as about 50° C.above the melting point of the hydrocarbon coating. The hydrocarboncoating may be picked-up by the melted matrix as it is atomized by therotation of the rotary shaft, which typically rotates at about 3,000 toabout 4,000 revolutions per minute (hereinafter may be abbreviated“rpm”). Generally, a residence time is about 10 to about 20 seconds whenthe temperature of the jacket and the rotary shaft are above the meltingpoint of the hydrocarbon coating. An exemplary mixer is sold under thetrade designation TURBULIZER® made by Hosokawa Bepex Corporation ofMinneapolis, Minn.

After leaving the mixer, the mixture can be cooled below the meltingpoint of the coating. The produced catalyst particles can have a maximumdimension of about 50 to about 5,000 microns, preferably about 50 to 500microns, more preferably less than about 130 microns, and optimally lessthan about 90 microns. The catalyst particles may be agglomerated intolarger spheres of about 1 centimeter in diameter that can easily behandled. The ferrous sulfate can be pelletized by using other methods,such as those methods disclosed in, e.g., U.S. Pat. No. 5,108,481.

Desirably, the dispersability of the catalyst in the hydrocarbon byusing the hydrocarbon coating may prevent agglomeration when storing andhandling the catalyst, and thus aides mixing and dispersing into ahydrocarbon feed. As an example, the catalyst can contain a core ofmonohydrate or moist heptahydrate with a coating of pitch. The catalystcan have a consistent iron concentration delivered to a hydroconversionsystem in a dry, hydrophobic, and free-flowing large particles. Thus,the catalyst can be easily crumbled and dissolved in a hot feed with,e.g., a roll crusher and screen, with a minimum of mess and no moisturepick-up, and hence, typically, without milling equipment.

ILLUSTRATIVE EMBODIMENTS

The following examples are intended to further illustrate the subjectparticle(s). These illustrative embodiments of the invention are notmeant to limit the claims of this invention to the particular details ofthese examples. These examples can be based on engineering calculationsand actual operating experience with similar processes.

Example 1

About 30 grams of paraffin wax is melted at about 60° C. in a flaskequipped with a mixer, such as a mixer sold under the trade designationL4RT by Silverson Machines, Inc. of East Longmeadow, Mass. Thetemperature is increased until the viscosity is reduced enough to allowthorough mixing at about 100° C. While stirring, about 60 grams of theiron sulfate monohydrate is added. The iron sulfate monohydrate can havea bulk density of 1.9 g/cc and a crystal density of 3.0 g/cc with avoidage of about 36.7%. After mixing for 5 minutes, the samples arecooled while mixing until the samples begin to gel. The gel is removed,hand-extruded to form droplets of about 5,000 microns in size, andallowed to harden.

Example 2

About 30 grams of pitch is melted at about 225° C. in a flask equippedwith a mixer, such as a mixer sold under the trade designation L4RT bySilverson Machines, Inc. of East Longmeadow, Mass. The pitch can beash-free and produced by collecting and fractionating a heavy product ofa slurry hydrocracker. The pitch may have a density of 1.185 g/cc. Thetemperature is increased until the viscosity is reduced enough to allowthorough mixing at about 300° C. A release of water vapor may occur dueto the relatively high temperature. While stirring, about 60 grams ofthe iron sulfate monohydrate is added. The iron sulfate monohydrate canhave a bulk density of 1.9 g/cc and a crystal density of 3.0 g/cc with avoidage of about 36.7%. The pitch can be in a volumetric amountequivalent to about 10% of the void volume of the iron sulfatemonohydrate particles for the purpose of binding the mass and sealingthe outside of the granules. After mixing for 5 minutes, the samples arecooled while mixing until the samples begin to gel. The gel is removed,hand-extruded to form droplets of about 5,000 microns in size, andallowed to harden.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The preceding preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

In the foregoing, all temperatures are set forth in degrees Celsius and,all parts and percentages are by weight, unless otherwise indicated.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention and, withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

1. A process for making a catalyst comprising an effective amount ofiron for catalyzing one or more reactions in a hydrocarbon conversionsystem, comprising: A) grinding particles comprising the effectiveamount of iron so substantially all the particles have a maximumdimension no larger than about 130 microns; and B) coating the particleswith an effective amount of one or more hydrocarbons to provide thecatalyst with improved flowability.
 2. The process according to claim 1,wherein the iron is at least partially comprised in at least one or morecompounds of an iron oxide, an iron sulfate, and an iron carbonate. 3.The process according to claim 1, wherein the iron is comprised in aniron sulfate.
 4. The process according to claim 1, wherein the iron iscomprised in at least one of an iron sulfate monohydrate and an ironsulfate heptahydrate.
 5. The process according to claim 1, wherein theone or more hydrocarbons is compatible with a feed for processing in thehydrocarbon conversion system.
 6. The process according to claim 1,wherein the one or more hydrocarbons has a melting point temperature ofno more than about 250° C.
 7. The process according to claim 1, whereinthe one or more hydrocarbons has a melting point temperature of no morethan about 80° C.
 8. The process according to claim 1, wherein the oneor more hydrocarbons comprises at least one of a wax, a pitch, adeasphalted oil, a petroleum resin, and a low molecular weight polymer.9. The process according to claim 1, wherein the coating has sufficientmoisture resistance to prevent agglomeration of the catalyst.
 10. Theprocess according to claim 6, wherein the one or more hydrocarbons iscompatible with a feed for the hydrocarbon conversion system.
 11. Theprocess according to claim 10, wherein the hydrocarbon conversion systemis a slurry reactor system.
 12. The process according to claim 1,wherein the weight ratio of the ground particles to the one or morehydrocarbons is about 200:1 to about 1:1.
 13. The process according toclaim 1, wherein a hammermill or a ball mill grinds the particles.
 14. Aslurry catalyst system, comprising: A) an upflow tubular reactorreceiving: 1) a hydrocarbon feed comprising one or more compounds havingan initial boiling point temperature of at least about 340° C.; and 2) aslurry catalyst composition, wherein the composition comprises: a) acatalytically effective amount of one or more compounds; and b) acoating comprising a hydrocarbon having a melting point temperature ofno more than about 250° C. for improving flowability of the slurrycatalyst composition.
 15. The slurry catalyst system according to claim14, wherein the one or more compounds comprises at least one of an ironsulfate monohydrate and an iron sulfate heptahydrate.